Thats probably because the Cordova plugins aren’t yet initialized and available when you load your routes. To overcome this, I’ve delayed the framework7 initialization and put my routes inside a function like this:

var f7app = new Framework7({
init: false,
...
}

Then my routes.js contains something like this:

function load_routes() {
return {
... regular routes object ...
}
}

And in my deviceready callback, I load the routes and initialize Framework7: